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| author | Marek Polacek <polacek@redhat.com> | 2014-08-07 08:12:04 +0000 |
|---|---|---|
| committer | Marek Polacek <mpolacek@gcc.gnu.org> | 2014-08-07 08:12:04 +0000 |
| commit | 044331a86cdee0427e7b8552307c9e83f7088979 (patch) | |
| tree | d7ba08e9040a1712a5107f8572a9ad61c05b7f13 /gcc/fold-const.c | |
| parent | ce597aedd79e646c4a5517505088d380239cbfa5 (diff) | |
| download | gcc-044331a86cdee0427e7b8552307c9e83f7088979.zip gcc-044331a86cdee0427e7b8552307c9e83f7088979.tar.gz gcc-044331a86cdee0427e7b8552307c9e83f7088979.tar.bz2 | |
fold-const.c (fold_binary_loc): Add folding of (PTR0 - (PTR1 p+ A) -> (PTR0 - PTR1) - A.
* fold-const.c (fold_binary_loc): Add folding of
(PTR0 - (PTR1 p+ A) -> (PTR0 - PTR1) - A.
c/
* c-typeck.c (pointer_diff): Remove P - (P + CST) optimization.
testsuite/
* gcc.dg/fold-reassoc-3.c: New test.
From-SVN: r213700
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 7180662..d444769 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -10831,6 +10831,19 @@ fold_binary_loc (location_t loc, if (tmp) return fold_build2_loc (loc, PLUS_EXPR, type, tmp, arg01); } + /* PTR0 - (PTR1 p+ A) -> (PTR0 - PTR1) - A, assuming PTR0 - PTR1 + simplifies. */ + else if (TREE_CODE (arg1) == POINTER_PLUS_EXPR) + { + tree arg10 = fold_convert_loc (loc, type, + TREE_OPERAND (arg1, 0)); + tree arg11 = fold_convert_loc (loc, type, + TREE_OPERAND (arg1, 1)); + tree tmp = fold_binary_loc (loc, MINUS_EXPR, type, arg0, + fold_convert_loc (loc, type, arg10)); + if (tmp) + return fold_build2_loc (loc, MINUS_EXPR, type, tmp, arg11); + } } /* A - (-B) -> A + B */ if (TREE_CODE (arg1) == NEGATE_EXPR) |